Outcomes of penetrating keratoplasty with imported donor corneas

To analyze factors influencing the surgical success of penetrating keratoplasty and long-term graft survival when using imported donor corneas.

Sixty-three donor corneas imported to Taipei from the Cincinnati Eye Bank from July 1992-June 1993 were used for penetrating keratoplasty. The corneal endothelium was examined using specular microscopy on arrival in Taiwan. The endothelial morphology and endothelial cell density (ECD) were compared with the photograph of the same cornea taken in the United States. The relationships of the surgical success rate with donor age, death to enucleation time, death to surgery time, and ECD were analyzed. The long-term graft survival and ECD of clear grafts were analyzed 4 years after surgery.

On specular microscopic examination. the imported corneas showed diminished endothelial reflection, blurred cellular borders, and increased dark areas, which were markedly different from the pictures of the corneal endothelium taken in the United States. The average ECD before transportation was 2,525+/-267/mm2 and decreased to 1,934+/-250/mm2 after transportation (p < 0.001), with an average endothelial cell loss of 590+/-247/mm2. The overall surgical success rate was 89% and did not correlate with any of the donor factors tested except death to surgery time. The surgical success rate decreased when the time from death to surgery was >7 days (p = 0.05), mainly because of poor reepithelialization. Four years after surgery, 24 grafts remained clear. The ECD had decreased by 72+/-5% in the clear grafts.

Our findings show that endothelial changes in imported donor corneas do occur after transportation, but the surgical success rate may not be influenced significantly if the penetrating keratoplasty is performed within 7 days after donor death. However, the ECD in the clear grafts 4 years after surgery is low.